Surfaces, such as pavement, commonly include an informational pattern to convey information to drivers and pedestrians. Informational patterns may be in the form of symbols, such as arrows, or the informational patterns may be words, such as "stop", "yield" and "RR Crossing". Surfaces may also bear informational patterns in the form of company logos and the like.
The most common approach to marking a pavement surface is to use stencils. Such stencils may be made of one or multiple pieces, and they may be reusable or made of material for one-time use only, for example masking tape. Typically, a stencil is placed on a pavement surface and a spray gun, brush, or other painting instrument is used to apply paint to the pattern-defining apertures in the stencil. To improve nighttime visibility on pavement, glass beads or other reflective material may be sprinkled on top of the paint.
There are a number of problems associated with the use of stencils to mark pavement or other traffic carrying surface. First, the selected surface must be blocked-off to protect workers from moving traffic. Even after a surface is blocked-off, workers often are required to hazardously labor adjacent to moving traffic.
Second, because of the large scale of traffic marking stencils, they are relatively cumbersome. A typical work truck is therefore limited to carrying only a small number of pavement symbol stencils. Thus, frequent trips to a base station are required to exchange stencils.
Stencils have to be carefully positioned and the paint applied to the stencil must be uniformly distributed in a selected thickness. For instance, low output and/or too rapid application of paint may result in a thinly applied paint layer. This results in premature wear of the applied pattern and additional inspection and reapplication costs.
Another problem with the use of stencils is that the paint that is used must be specifically formulated for slow drying to insure that there is sufficient time to apply glass beads. Since the paint is slow drying, it is usually necessary to leave the selected surface marked-off for a period of time after the work is completed. Consequently, the marked-off surface disrupts traffic for an extended period of time. In addition, the work crew is required to return to the site after the drying process is completed to remove protective barriers.
Still another problem with the use of stencils is that they require periodic cleaning to prevent paint build-up. This cleaning requirement adds to the cost associated with the use of stencils.